SYNTHESIS, CHARACTERIZATION, AND USE OF NANOMODIFIED SUGARCANE - - PowerPoint PPT Presentation

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Sep 23, 2023 321 likes •587 views

SYNTHESIS, CHARACTERIZATION, AND USE OF NANOMODIFIED SUGARCANE BAGASSE FOR THE SORPTION OF HEXAVALENT CHROMIUM Thais E. Abilio 1 , Beatriz C. Soares 1 , Julia C. Jos 1 , Juliana T.T. Carvalho 1 , Gergia Labuto 2 , Elma N.V.M. Carrilho 1,3 1

SLIDE 1

SYNTHESIS, CHARACTERIZATION, AND USE OF NANOMODIFIED SUGARCANE BAGASSE FOR THE SORPTION OF HEXAVALENT CHROMIUM

Thais E. Abilio1, Beatriz C. Soares1, Julia C. José1, Juliana T.T. Carvalho1, Geórgia Labuto2, Elma N.V.M. Carrilho1,3

1 Laboratory of Polymeric Materials and Biosorbents, Federal

University of São Carlos, Brazil.

2 Department of Chemistry, Federal University of São Paulo, Brazil. 3 Department of Natural Sciences, Mathematic and Education,

Federal University of São Carlos, Brazil.

SLIDE 2

Toxic metals are cumulative, not naturally degraded, either biologically or chemically, and require special treatment as they are harmful to living

rganisms.

SLIDE 3

Noticias

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HEAVY METAL – CHROMIUM

Cr(III) is considered an essential nutrient to humans Cr(VI) is considered a toxic and carcinogenic agent

SLIDE 5

H2CrO4 → H+ + HCrO4- (pH = 1 – 6) HCrO4 → H+ + CrO42- (pH > 7) HEXAVALENT CHROMIUM – Applications

Stainless steel industries, electroplating processes, dyes and leather tanneries, and in wood preservation processes

In aqueous solution:

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AN IMPORTANT FIELD

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BIOSORPTIO N

CHOICES OF BIOSORBENTS

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SUGARCANE

~ 616 millions of tons 2018/19

Assessment of biomasses in the sorption of Cr(VI) from aqueous medium

Sarker, et al., 2017

Dried powdered bagasse

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THE UNIVERSITY FARM – SUGARCANE CROP

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Sugarcane Bagasse

BIOMASSES USED

Cleaning with purified H2O Drying at 50 ºC

Ground to 0.12 mm

1.5 g of biomass

Leaching with HCl 1 mol/L Modification

Conditioned with 0.005 mol/L KCH3COO/CH3COOH solution at pH 5.5

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CHARACTERIZATION OF THE ADSORBENTS

X-Ray Diffraction (XRD)

Identification of crystalline structures of the materials;

Scanning Electron Microscopy (SEM)

It is possible to obtain external images showing the surface of the materials;

Fourier

Transform Infrared Spectroscopy (FTIR)

Detects the absorption in a characteristic region, identifying the functional groups in the materials.

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Fourier Transform Infrared Spectroscopy X-Ray Diffraction (XRD)

Scanning Electron Microscopy

MSB-NP-Cr NP-SB-Cr

MSB-NP-Cr

NP-SB-Cr

SLIDE 13 30 29 28 27 5 4 3 2 1 10 9 8 7 6 15 14 13 12 11 20 19 18 17 16 25 24 23 22 21 26

Fe2+

(aq) + 2Fe3+ (aq) + 8 OH- (aq) → Fe3O4 (s) + 4H2O(l)

Fe3O4 (s) + SB (s)→ SB-Fe3O4 (s) (Biomass impregnated with magnetite)

SYNTHESIS OF MAGNETITE NANOPARTICLES

30 min 30 min 80 ºC

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EFFECT OF MAGNETIZATION

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pH ASSESSMENT

1 2 3 4 5 6 0,1 0,2 0,3 0,4

SB-NP MSB-NP

pH Metal Retained (m g/g)

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KINETIC STUDIES

100 mg of biomass 10 mL of Cr(VI) solution Constant agitation to the times 5, 10, 30, 60, 90, 120, and 150 min Flame Atomic Absorption Spectrometry Separation by Nd magnet

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KINETICS OF Cr(VI) SORPTION BY in natura AND ACID WASHED NANOMODIFIED SUGARCANE BAGASSE

20 40 60 80 100 120 140 160 0,1 0,2 0,3 0,4 0,5

SB-NP MSB-NP

Time(min) M etal Retained (m g/g)

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SLIDE 19

Data of pseudo-first and pseudo-second order kinetics of in natura (SB-NP) and acid washed (MSB-NP) nanomodified sugarcane bagasse.

In natura (SB-NP) and acid washed (MSB-NP) nanomodified sugarcane bagasse; For pseudo 1st order the slope = k1 (min−1). For pseudo 2nd order the angular parameter = k2 (g mg−1 min−1), n = 3. 100 mg of biosorbent suspended in 10 mL of 100 mg/L Cr(VI) solution. n = 3.

CHEMICAL NATURE

SLIDE 20

Separation by centrifugation or Nd magnet Biosorbent + Cr(VI) Supernatant Agitation for 30 min.

Cr determination by FAAS 100 mg of in natura or nanomodified sugarcane bagasse biomass 10 mL Cr(VI) solution

BATCH PROCEDURE FOR Cr(VI) SORPTION BY in natura OR NANOMODIFIED SUGARCANE BAGASSE

SLIDE 21 SB Cr(VI) adsorbed Hill T emkin D-R Sips Freundlich Langmuir Ce (mg/L) Q e (m g /g )

20 40 60 80 100 120 0,0 0,5 1,0 1,5 2,0

SB-NP Ce (mg/L) Qe (mg/g)

SLIDE 22

Values

experimental sorption capacity (Qexp), isotherms parameters and χ2 error evaluation for Cr sorption by NP SB, and SB-NP

SD = Standard Deviation; SE = Standard Error provided by fitting the model to the experimental data; n = 3. NP – magnetic nanoparticles SB – sugarcane bagasse SB-NP – nanomodified sugarcane bagasse The lower the χ2, higher similarities between the experimental isotherms and the predicted model

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Values

experimental sorption capacity (Qexp), isotherms parameters and χ2 error evaluation for Cr sorption by NP, SB, and SB-NP

SD = Standard Deviation; SE = Standard Error provided by fitting the model to the experimental data; n = 3. NP – magnetic nanoparticles SB – sugarcane bagasse SB-NP – nanomodified sugarcane bagasse The lower the χ2, the higher similarities between the experimental isotherms and the predicted model

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 Sugarcane bagasse showed great potential in the sorption of Cr(VI) in aqueous medium.  Chemical modification did not show significant improvement in the sorption of Cr(VI) – Sugarcane bagasse can be used in natura!!!

Chemical Modification

CONCLUSIONS

Biomass Magnetization of the biomass Industrial Application

 The magnetite, besides facilitating the removal of the biosorbent from the medium, increases the sorption capacity;  Both in natura and nanomodified sugarcane bagasse can be used for water decontamination.

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THE BIOSORPTION GROUP

Polymer Materials and Biosorbents Laboratory

Federal University of São Carlos

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